Contacts not working after System 27 installation

What does “not working” mean? The macOS Contacts works normally for me, and if it was systemically broken in macOS 27 there would be millions of people affected. Therefore, there is a problem with your setup.

If you sync contacts with iCloud, then aign out of then back into your Apple Account.

Have you rebooted your Mac? If not, that's the first step. If that does not help, then see if the problem is present when you boot in safe mode. That process performs some system cleanup and clears caches, andalso disables 3rd party extensions that may cause problems.

Start up your Mac in safe mode - Apple Support

If that does not correct the issue, test in a new user account. A newly-created user account will have all settings at default, and if the issue does not occur in that new account then it provides guidance on what may need to be changed to correct the issue.

Add a user or group on Mac - Apple Support

Once the testing is complete, the new account can easily be deleted.

Delete a user or group on Mac – Apple Support

Those steps will help to isolate the problem.

It might help to download and run EtreCheck, written by a long-time forum member. The free version is fine. Post the full report using the Additional Text button. No personal information is revealed. 

Contacts Not Working After Installing macOS 27

If Contacts stopped working after installing macOS 27, the update may have affected the app, your contact database, or account syncing.

Try these steps first. They’re safe and won’t require deleting your contacts.

1. Check what’s going wrong

• Contacts won’t open: Press Option + Command + Esc, select Contacts, and click Force Quit. Then reopen it.
• Contacts opens, but names are missing: Check your contact accounts and syncing settings.
• Contacts freezes or crashes: Restart your Mac and try again.
• You see an error message: Make a note of the exact message.

2. Check your contact accounts

1. Open the Apple menu  and go to System Settings → Internet Accounts.
2. Select your iCloud, Google, or other contacts account.
3. Make sure Contacts is enabled, if available.
4. Open Contacts and select All Contacts in the sidebar.

If you use iCloud, visit iCloud.com/contacts to check whether your contacts are still there.

3. Check for a software update

Go to System Settings → General → Software Update and check whether a newer version is available. Back up your Mac before installing any update.

If Contacts stopped working immediately after the upgrade, the issue may be related to the new macOS version.

Let's narrow it down

What happens when you open Contacts?

• Contacts won’t open.
• Contacts opens but freezes or shows a spinning wheel.
• Contacts opens, but names are missing or won’t sync.
• Contact search isn’t working.
• Something else is happening.

Also, if you know your exact macOS version (such as 27.0 or 27.0.1), please include it.

With those two details, we can focus on the most likely fix without risking your contacts.

I have the same problem. for me it is accessing contacts via apple's Messages.app - when trying to add an sms number received via sms to an existing contact, contacts crashes the second i try to assign a custom label, or any label except "phone" to the number I'm adding. In addition, contacts repeated crashes eventually when searching for contacts, editing several contacts in a row, or working with more than one contact source, like google's contact system or outlooks. logs also indicate never ending sandbox blocking contacts access to icloud, in particular, but i don't think that's related to contact.app's problems, it's just not stable since 27.0 on macos. I also lost a lot of contact entries, thankfully I had backups on icloud, an now I always keep a copy of contact entries exported to my nas, just in case it crashes while i try to do things like resolve duplicates, that's how often it's crashing for me. I know you high point community members NEVER have problems, a reply that seems to always occur in a post that is about having a problems with an apple supplied app, but it really is a problem for some people. and there is nothing unique about my setup.